Question

What I think I know so far:

so $this-> is to access a function/var outside its own function/var ?

but how does $this-> know if its a function or a variable ?

why we refer to a var like this $this->data instead of this $this->$data ?

Answer 1

$this refers to the current object that a method has been invoked on. It knows if it’s a function if there is a pair of parentheses at the end. We use the former syntax because $this->$data means look at the field whose name is $data; e.g. $this->foo if $data == 'foo'